Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Ashish Sarkar ¹, Asit K. Guha ¹

Affiliations
1 Department of Geology and Geophysics, IIT, Kharagpur - 721302, IN

Abstract

Paleontologic Time Series (PTS) analysis in both time and frequency domains on eight series of abundance data of Globorotalia menardii and total planktonic foraminifera from top core sections of DSDP Sites 219, 220 and 241 of Northern Indian Ocean depict cyclic variation presumably due to fluctuations in the Pleistocene paleo-temperature. At these sites, the relative dominance of planktonic foraminifera and G. menardii, uniform effect of post-mortem transport on foraminiferal tests of different sizes and differential sediment accumulation rate are revealed from the nature of energy distribution in the spectra, identical nature of major peaks and varying cycle lengths respectively.

Keywords

Paleontologic Time Series (PTS), Deep Sea Drilling Project (DSDP), Pleistocene, Planktonic Foraminifera.

Full Text

     

Ashish Sarkar ¹, Asit K. Guha ¹

Affiliations
1 Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur-721302, IN

Abstract

The Quaternary planktonic foraminiferal assemblages from DSDP Sites 219,220 and 241 in Northern Indian Ocean have been analysed in terms of diversity changes along the depth of each core. For an understanding of the population dynamics in the region and its relation to the paleoclimatic events (Ericson zones), relative abundance at family and species levels have been studied. Different indices of diversity viz., S, D, Hand E have been worked out and correlated with that of the oscillation in paleoclimatic record, which is based on the fluctuation in abundance of Globorotalia menardii along the depth of the core. It has been noted that during the Quaternary, relative abundance of different species and changes in diversity indices match well with that of the Ericson paleoclimatic zonation, enabling recognition of different stages of glacial and interglacial episodes in Northern Indian Ocean.

Keywords

Palaeontology, Foraminifera, Palaeoclimate, Quaternary, Northern Indian Ocean.

Full Text

     

Ashish Sarkar ¹

Affiliations
1 School of Petroleum Technology, Pandit Deendayal Petroleum University, Gandhinagar 382 007, IN

Abstract

No Abstract.

Full Text